MedPath

Study to Evaluate the Efficacy of Tenapanor as Adjunctive Therapy to Phosphate Binder Therapy

Phase 2
Completed
Conditions
Hyperphosphatemia
Interventions
Registration Number
NCT03824587
Lead Sponsor
Ardelyx
Brief Summary

This is a randomized, double-blind, placebo-controlled study to evaluate the effect of tenapanor on change in s-P levels when tenapanor is administered orally, twice daily for 28 days as adjunctive therapy to ESRD subjects with hyperphosphatemia on stable phosphate binder therapy.

Detailed Description

The study consists of a Screening visit; a Run-in Period of at least 2 weeks and up to 4 weeks, where existing phosphate binder treatment is maintained; and a 4-week Double-Blind Treatment Period.

At Screening, a subject must be on thrice daily phosphate binder therapy and have a serum phosphate (s-P) level ≥5.5 and ≤10.0 mg/dL to qualify for entering the study. s-P will be measured at each visit during the run-in period to enable the evaluation of the s-P randomization criteria.

Subjects who qualify to enroll in the study will be randomized in a 1:1 ratio to receive tenapanor or placebo while continuing their existing phosphate binder treatment.

During the Double-Blind Treatment Period, subjects will receive tenapanor or placebo starting at a dose of 30 mg bid

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
236
Inclusion Criteria
  • Signed and dated informed consent prior to any study specific procedures.
  • Males or females aged 18 to 80 years, inclusive, at Screening
  • Females must be non-pregnant, non-lactating and either be post-menopausal for at least -2 months, have documentation of irreversible surgical sterilization, use of acceptable -contraceptive method, or sexual abstinence, or a sterile sexual partner from Screening -until 30 days after the last subject visit.
  • Males must agree to avoid fathering a child (or donating sperm), and therefore be either sterile (documented) or agree to use approved methods of contraception, from the time of enrollment until 30 days after end of study.
  • Chronic maintenance hemodialysis (HD) 3x/week for at least 3 months or chronic maintenance peritoneal dialysis (PD) for a minimum of 6 months.
  • If receiving active vitamin D or calcimimetics, the dose should have been unchanged for the last 4 weeks prior to Screening.
  • Kt/V ≥1.2 at most recent measurement prior to Screening.
  • Prescribed and taking phosphate binder medication at least 3 times per day, and the prescribed dose should have been unchanged during the last 4 weeks prior to Screening.
  • Serum phosphorus levels must be ≥5.5 and ≤10.0 mg/dL at Screening and the end of the run-in period, analyzed at the central laboratory used in the study.
Read More
Exclusion Criteria
  • Severe hyperphosphatemia defined as having an s-P level >10.0 mg/dL on phosphate-binders at any time point during routine clinical monitoring for the 3 preceding months before Screening.
  • Serum/plasma parathyroid hormone >1200 pg/mL.
  • Clinical signs of hypovolemia at Screening as judged by the Investigator.
  • History of inflammatory bowel disease (IBD) or irritable bowel syndrome with diarrhea (IBS-D).
  • Scheduled for living donor kidney transplant or plans to relocate to another center during the study period.
  • Use of an investigational agent within 30 days prior to Screening.
  • Involvement in the planning and/or conduct of the study (applies to both Ardelyx/Contract Research Organization (CRO) staff and/or staff at the study site).
  • If, in the opinion of the Investigator, the subject is unable or unwilling to fulfill the requirements of the protocol or has a condition which would render the results uninterpretable.
Read More

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
Tenapanor 30 mg BIDPhosphate Binder AgentsDuring the Double-Blind Treatment Period, subjects will receive tenapanor starting at a dose of 30 mg bid (three 10 mg tablets each time). Investigators may decrease or increase the dose of study medication based on s-P levels and/or gastrointestinal (GI) tolerability in 10 mg increments to a minimum of 10 mg bid or a maximum of 30 mg bid at any time during the Double-Blind Treatment Period.
PlaceboPlacebosame size, weight and appearance of experimental drug
PlaceboPhosphate Binder Agentssame size, weight and appearance of experimental drug
Tenapanor 30 mg BIDTenapanorDuring the Double-Blind Treatment Period, subjects will receive tenapanor starting at a dose of 30 mg bid (three 10 mg tablets each time). Investigators may decrease or increase the dose of study medication based on s-P levels and/or gastrointestinal (GI) tolerability in 10 mg increments to a minimum of 10 mg bid or a maximum of 30 mg bid at any time during the Double-Blind Treatment Period.
Primary Outcome Measures
NameTimeMethod
Change in Serum Phosphorus (s-P) Level From Baseline to Week 4.4 Weeks (28 days randomization period; from baseline to week 4)

Difference in mean change from baseline in s-P level at Week 4 between the tenapanor and placebo groups.

Secondary Outcome Measures
NameTimeMethod
Relative Change From Baseline in cFGF23 at Week 44 Weeks (28 days randomization period)

cFGF23 at Week 4/baseline cFGF23 - 1

s-P Response at Week 44 Weeks (28 days randomization period)

Achieving an s-P level \<5.5 mg/dL

Relative Change From Baseline in iFGF23 at Week 44 Weeks (28 days randomization period)

iFGF23 at Week 4/baseline iFGF23 - 1

Trial Locations

Locations (48)

Nephrology Consultants, LLC

🇺🇸

Huntsville, Alabama, United States

Mountain Kidney & Hypertension Associates, P.A.

🇺🇸

Asheville, North Carolina, United States

California Institute of Renal Research - Chula Vista

🇺🇸

Chula Vista, California, United States

Chabot Nephrology Medical Group

🇺🇸

Union City, California, United States

North America Research Institute

🇺🇸

Lynwood, California, United States

Central Coast Nephrology

🇺🇸

Salinas, California, United States

US Renal Care - Waxahachie

🇺🇸

Mansfield, Texas, United States

Northwell Health

🇺🇸

Great Neck, New York, United States

North America Research Institute - San Dimas

🇺🇸

San Dimas, California, United States

Nova Clinical Research, LLC

🇺🇸

Bradenton, Florida, United States

Southeast Renal Research

🇺🇸

Beverly Hills, California, United States

Dialysis Clinic, Inc - Albany GA

🇺🇸

Albany, Georgia, United States

Northeast Clinical Research Center

🇺🇸

Bethlehem, Pennsylvania, United States

US Renal Care - Mesquite

🇺🇸

Mesquite, Texas, United States

Dialysis Clinic, Inc - Boston/Somerville

🇺🇸

Boston, Massachusetts, United States

Med Center Dialysis

🇺🇸

Houston, Texas, United States

University of Cincinnati (UC) - Department of Nephrology

🇺🇸

Cincinnati, Ohio, United States

Total Research Group, LLC

🇺🇸

Miami, Florida, United States

InterMed Consultants

🇺🇸

Minneapolis, Minnesota, United States

Clinical Advancement Center, PLLC

🇺🇸

San Antonio, Texas, United States

Durham Nephrology Associates

🇺🇸

Durham, North Carolina, United States

US Renal Care - Pleasanton Road

🇺🇸

San Antonio, Texas, United States

Nephrology and Hypertension Associates, LTD

🇺🇸

Tupelo, Mississippi, United States

Kidney Specialists of Southern Nevada

🇺🇸

Las Vegas, Nevada, United States

Knoxville Kidney Center, PLLC

🇺🇸

Knoxville, Tennessee, United States

Sierra Nevada Nephrology Consultants

🇺🇸

Reno, Nevada, United States

US Renal Care Pine Bluff

🇺🇸

Pine Bluff, Arkansas, United States

Dialysis Clinic, Inc - North Brunswick

🇺🇸

North Brunswick, New Jersey, United States

Renal Associates of Baton Rouge

🇺🇸

Baton Rouge, Louisiana, United States

Boise Kidney & Hypertension, PLLC - Meridian

🇺🇸

Caldwell, Idaho, United States

South Carolina Nephrology & Hypertension Center Inc.

🇺🇸

Orangeburg, South Carolina, United States

Columbia Nephrology Associates, P.A.

🇺🇸

Columbia, South Carolina, United States

DCI - Spartanburg

🇺🇸

Spartanburg, South Carolina, United States

Genesis Clinical Trials

🇺🇸

Tampa, Florida, United States

Renal Medicine Associates

🇺🇸

Albuquerque, New Mexico, United States

Paragon Health PC - Nephrology Center

🇺🇸

Kalamazoo, Michigan, United States

US Renal Care - Westover Hills

🇺🇸

San Antonio, Texas, United States

Southeastern Nephrology Associates - Wilmington

🇺🇸

Wilmington, North Carolina, United States

DaVita Clinical Research - Santa Fe Spring

🇺🇸

Montebello, California, United States

American Institute of Research

🇺🇸

Whittier, California, United States

South Florida Research Institute

🇺🇸

Lauderdale Lakes, Florida, United States

Polack Renal, LLC (SMO)

🇺🇸

Saint Louis, Missouri, United States

Mountain Kidney and Hypertension Associates

🇺🇸

Asheville, North Carolina, United States

U.S. Renal Care - Gallup

🇺🇸

Gallup, New Mexico, United States

Dialysis Clinic, Inc - Kansas City

🇺🇸

Kansas City, Missouri, United States

Omega Research Consultants, LLC

🇺🇸

Orlando, Florida, United States

Clinical Research Consultants, LLC

🇺🇸

Kansas City, Missouri, United States

Horizon Research Group - Coral Gables

🇺🇸

Coral Gables, Florida, United States

© Copyright 2025. All Rights Reserved by MedPath